The role of fibres and the hypodermis in Compositae melanin secretion

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dc.contributor.authorDe-Paula, Orlando Cavalari
dc.contributor.authorMarzinek, Juliana
dc.contributor.authorOliveira, Denise Maria Trombert
dc.contributor.authorMachado, Silvia Rodrigues [UNESP]
dc.contributor.institutionUniversidade Federal do Paraná (UFPR)
dc.contributor.institutionUniversidade Federal de Uberlândia (UFU)
dc.contributor.institutionUniversidade Federal de Minas Gerais (UFMG)
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-27T11:27:29Z
dc.date.available2014-05-27T11:27:29Z
dc.date.issued2013-01-01
dc.description.abstractMelanins are dark, insoluble pigments that are resistant to concentrated acids and bleaching by oxidising agents. Phytomelanin (or phytomelan) is present in the seed coat of some Asparagales and in the fruits of some Compositae. In Compositae fruits, melanin is deposited in the schizogenous spaces between the hypodermis and underlying fibrous layer. Phytomelanin in Compositae is poorly understood, and there are only speculations regarding the cells that produce the pigment and the cellular processes involved in the secretion and polymerisation of phytomelanin. This report describes the cellular processes involved in the secretion of phytomelanin in the pericarp of Praxelis diffusa, a species with a structure typical of the family. The ovaries and fruits at different stages were fixed and processed according to the standard methods of studies of light microscopy and transmission electron microscopy. Hypodermal cells have abundant rough endoplasmic reticulum and mitochondria, and the nuclei have chromatin that is less dense than other cells. These characteristics are typical of cells that synthesise protein/amino acids and suggest no carbohydrate secretion. The fibres, however, have a dense cytoplasm rich in the Golgi bodies that are associated with vesicles and smooth endoplasmic reticulum, common characteristics of carbohydrate secretory cells. Our results indicate that the hypodermal cells are not responsible for the secretion of phytomelanin, as previously described in the literature; in contrast, this function is assigned to the adjacent fibres, which have an organisation typical of cells that secrete carbohydrates. © 2012 Elsevier Ltd.en
dc.description.affiliationDepartamento de Botânica Setor de Ciências Biológicas Universidade Federal do Paraná, Curitiba, PR
dc.description.affiliationInstituto de Biologia Universidade Federal de Uberlândia, Uberlândia, MG
dc.description.affiliationDepartamento de Botânica Instituto de Ciências Biológicas Universidade Federal de Minas Gerais, Belo Horizonte, MG
dc.description.affiliationDepartamento de Botânica Instituto de Biociências UNESP-Universidade Estadual Paulista, Botucatu, SP
dc.description.affiliationUnespDepartamento de Botânica Instituto de Biociências UNESP-Universidade Estadual Paulista, Botucatu, SP
dc.format.extent312-316
dc.identifierhttp://dx.doi.org/10.1016/j.micron.2012.08.003
dc.identifier.citationMicron, v. 44, n. 1, p. 312-316, 2013.
dc.identifier.doi10.1016/j.micron.2012.08.003
dc.identifier.issn0968-4328
dc.identifier.lattes2653496390637757
dc.identifier.scopus2-s2.0-84870724009
dc.identifier.urihttp://hdl.handle.net/11449/74186
dc.identifier.wosWOS:000312925300034
dc.language.isoeng
dc.relation.ispartofMicron
dc.relation.ispartofjcr1.728
dc.relation.ispartofsjr0,624
dc.rights.accessRightsAcesso restrito
dc.sourceScopus
dc.subjectAsteraceae
dc.subjectCypsela
dc.subjectFruit
dc.subjectPhytomelan
dc.subjectPhytomelanin
dc.subjectSecretory structure
dc.subjectCellular process
dc.subjectCompositae
dc.subjectEndoplasmic reticulum
dc.subjectGolgi bodies
dc.subjectHypodermal cells
dc.subjectRough endoplasmic reticulums
dc.subjectSecretory cells
dc.subjectSeed coats
dc.subjectStandard method
dc.subjectCarbohydrates
dc.subjectCell membranes
dc.subjectFruits
dc.subjectPhysiology
dc.subjectTransmission electron microscopy
dc.subjectCytology
dc.subjectmelanin
dc.subjectbiosynthesis
dc.subjectcytoplasm
dc.subjectendoplasmic reticulum
dc.subjectflower
dc.subjectGolgi complex
dc.subjectmetabolism
dc.subjectmitochondrion
dc.subjectsecretion (process)
dc.subjectsubcutaneous tissue
dc.subjecttransmission electron microscopy
dc.subjectCytoplasm
dc.subjectEndoplasmic Reticulum
dc.subjectFlowers
dc.subjectGolgi Apparatus
dc.subjectMelanins
dc.subjectMicroscopy, Electron, Transmission
dc.subjectMitochondria
dc.subjectSubcutaneous Tissue
dc.subjectAsparagales
dc.subjectPraxelis diffusa
dc.titleThe role of fibres and the hypodermis in Compositae melanin secretionen
dc.typeArtigo
dcterms.licensehttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
unesp.author.lattes2653496390637757
unesp.author.orcid0000-0003-1918-2433[3]
unesp.author.orcid0000-0002-8089-2082[1]
unesp.author.orcid0000-0002-4482-0655[2]
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Biociências, Botucatupt

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